I recently purchased a new western mountaineering sleeping bag (Puma MF) from Moosejaw. Long story short, I found that the bag was manufactured more than 4 years ago, in 2014, the price tags have faded to yellowish color, and the storage sack (not the compression sack) smells like an old library book.

Naturally, the fact that the bag is 4 years old despite being new throws me off a bit due to the high price hence the high expectation.

The indecision is whether I should return the sleeping bag? The main concern here is the old bag will have a shorter lifespan and provide worse insulation than a recently manufactured counterpart. Please let me know whether my concerns are unfounded.

  • 1
    If any item you purchase smells bad/old, and isn't cheese - take it back and either haggle or return it.
    – Stian
    Nov 30, 2018 at 23:47
  • @StianYttervik In my case, the issue is I got a great deal from the seller and the same bag is no longer in stock, so no replacement is possible..
    – Kun
    Dec 2, 2018 at 3:05
  • Well then it is different. Throw away and replace the storage bag. Use the sleeping bag. Perhaps don't trust the minimum temperature the first trip. After that you have experience.
    – Stian
    Dec 2, 2018 at 9:24

2 Answers 2


If the bag was compressed most of the time during the storage it may provide less insulation than a recently produced one.

The other thing is, if the bag has caught mildew, you might not be able to get rid of the smell. Or, if the smell goes away after washing, it may develop again. Check for mildew (image) - if there are any small black or similar dots anywhere, I would return it.

  • The bag was stored in the original storage sack instead of a compression sack, so my best guess is it was not stored compressed. I do not notice any black dots on the sleeping bag shell, but maybe the down has caught mildew and is not reflected on the shell since the shell is made of synthetic material and is of a darker color.
    – Kun
    Nov 30, 2018 at 17:03
  • It's then the smell. You can ask someone else if it smells like mildew. My experience is when a cloth catches mildew, even if you do not see it, it may be hard to get rid of completely, so it develops again.
    – Jan
    Nov 30, 2018 at 17:12

You should consider water repellency.

Down does not hold heat once it is wet. Unlike synthetic fillings. This is particularly true of older down products.

The only real innovation in down technology over the last few years has been the introduction of durable water repellent (DWR) down fills. Down with this treatment tends to repel water and is warmer when damp or wet.

Your year is right on the cusp of whether the down in the bag has been treated for water repellency. Read the specs, that should tell you. If the down is not water repellent, you might want to try to return it and get one that is for the same money.

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